As observers of a meteor that crashed in Russia’s Chelyabinsk region today can attest, near-earth objects that enter the earth’s atmosphere can wreak destruction. But these objects, which also include comets and asteroids, also provide clues to the solar system’s origins and could someday serve as stepping-stones to space exploration. In this podcast, Manager of NASA’s Near-Earth Objects program, Donald Yeomans, discusses the ongoing quest to find near-earth objects before they find us.

After traveling through space for seven years, NASA's MESSENGER spacecraft began orbiting the planet Mercury in March, 2011. In this podcast, join MESSENGER's principal investigator Sean Solomon as he describes how the spacecraft's specialized instruments are collecting information that is key to understanding terrestrial planet evolution.

In the next 30 years, global population is estimated to surpass nine billion people. Will there be too many people, too little food? In this podcast, join NBC News Chief Science and Health correspondent Robert Bazell and a round-table of food experts as they discuss how climate, politics and economics impact food systems and food security.

Guests include activist and best-selling author Raj Patel, geneticist Molly Jahn, and chef and UNICEF ambassador Marcus Samuelsson.

National Geographic explorer Tierney Thys divides her time between research on the giant ocean sunfish and making science education films. In this podcast, join Ms. Thys in a discussion about how science and art can be used to promote the ocean conservation movement.

Often overlooked root vegetables such as turnips and rutabaga can have a major impact on the Earth’s ecosystem and biodiversity. In this podcast, join chef Alex Guarnaschelli and Eleanor Sterling, Director of the Museum’s Center for Biodiversity, in a discussion about how our food shopping choices can affect sustainable agriculture.